I'm curious about what was going on in the minds of the parents, who so vociferously wanted the GF OUT. If they didn't know how much pain she was in, or how difficult moving had become for her, then what did they imagine her reasons were for wanting to stay an extra day in that room? Did they think she didn't want to leave? They can't have thought that she was looking for a place to "crash"; they knew she had a home of her own to go to. Did they think she was just being lazy?
I have had houseguests who were unable to leave on their expected departure date due to everything from illness, natural disasters, and flight cancellations. It happens....and I wonder if the parents would have acted differently if GF's reluctance to leave would've been caused by a cancelled flight....or inclement weather. (Maybe not - judging by the blizzard story!!) In any event, sometimes houseguests, despite their best intentions, are unable to leave when one expects them to. I think the parents were very ungracious.
And I definitely think that the BF should move out!!